All total, 474 operators in 138 countries are investing in LTE networks around the world, with a breakdown of 421 “firm operator commitments” to build networks in 128 countries, 53 additional countries engaged in trials and studies in 10 more countries. GSA predicts there will be 260 commercial LTE networks running in 93 countries by the end of this year.

Needless to say, LTE is the literal future of wireless, delivering peak downlink speeds of up to 150 Mbps in enhanced configurations. LTE supports HD voice through Voice over LTE (VoLTE). The VoLTE standard incorporates the AMR-WB codec as its default.

VoLTE is currently in commercial operation with several South Korean carriers. A number of carriers around the globe are running VoLTE trials, while AT&T and Verizon have vowed rollouts by 2014.